An ease-off tooth surface redesign for spiral bevel gears considering misalignment under actual working conditions

To improve the loaded performance of spiral bevel gears, a novel tooth surface redesign method considering misalignment is proposed based on ease-off. First, the digital features of the contact pattern were extracted, and the equivalent misalignment was obtained by an optimal method according to the minimum deviation of the contact path. Second, a pinion target surface whose performance under misalignment was consistent with the original gear in standard position was built, and a pinion surface with good meshing performance under misalignment was redesigned with equivalent misalignment. Third, the flank modification was carried out to cut down on the loaded transmission error of gear under misalignment. Through simulations, it is found the transmission error and the contact path of redesign gear considering misalignment were the same as original gear in standard position. The loaded transmission error amplitude of original gear under misalignment was 43.91% higher than original gear in standard position, and the loaded transmission error amplitude of redesign gear after optimization under misalignment was 44.73% lower than original gear in standard position and 61.60% lower than original gear under misalignment. The tooth surface stress of redesigned gear after optimization under misalignment was also significantly improved. This proposed redesign method, which considers misalignment on the basis of ease-off, can greatly improve the loaded meshing quality of gear under actual working conditions.